Bump kotlinVersion from 1.7.20 to 1.7.21

Bumps `kotlinVersion` from 1.7.20 to 1.7.21.

Updates `jvm` from 1.7.20 to 1.7.21
- [Release notes](https://github.com/JetBrains/kotlin/releases)
- [Changelog](https://github.com/JetBrains/kotlin/blob/master/ChangeLog.md)
- [Commits](https://github.com/JetBrains/kotlin/commits)

Updates `plugin.spring` from 1.7.20 to 1.7.21
- [Release notes](https://github.com/JetBrains/kotlin/releases)
- [Changelog](https://github.com/JetBrains/kotlin/blob/master/ChangeLog.md)
- [Commits](https://github.com/JetBrains/kotlin/commits)

Updates `plugin.jpa` from 1.7.20 to 1.7.21
- [Release notes](https://github.com/JetBrains/kotlin/releases)
- [Changelog](https://github.com/JetBrains/kotlin/blob/master/ChangeLog.md)
- [Commits](https://github.com/JetBrains/kotlin/commits)

---
updated-dependencies:
- dependency-name: jvm
  dependency-type: direct:production
  update-type: version-update:semver-patch
- dependency-name: plugin.spring
  dependency-type: direct:production
  update-type: version-update:semver-patch
- dependency-name: plugin.jpa
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

build.gradle.kts

@@ -14,7 +14,7 @@ repositories {
 }
 
 plugins {
-    val kotlinVersion = "1.7.20"
+    val kotlinVersion = "1.7.21"
     id("org.springframework.boot") version "2.7.5"
     kotlin("jvm") version kotlinVersion
     kotlin("plugin.spring") version kotlinVersion